Apple made its first foray into British television yesterday, and immediately found itself facing questions over the costs of its video downloads, which observers said were forcing British consumers to pay much higher prices than their US counterparts.

After years of speculation, the iPod maker launched its UK television download service, a project that allows customers to buy a handful of American television series through the company's massively popular iTunes Store.

But some experts said the service - whose offerings, for £1.89 a show, include the fictional series Lost, plus Ugly Betty, and Desperate Housewives - was much more expensive than in the US. The same purchases from the American iTunes Store, where television shows have been available for almost two years, cost just 99p ($1.99) an episode.

"The thing is that British TV viewers already have another place to go to catch up on programmes they have missed, thanks to download services like the BBC iPlayer, which is free," said Mark Mulligan, a technology analyst with Jupiter Research. "I wouldn't be surprised if they had to change their prices soon: we're in a situation where everything is always more expensive in Britain."

Apple refused to comment on how it arrived at the video download prices. The European commission this year decided to investigate the company over the pricing of iTunes tracks. That inquiry was prompted by a complaint from the consumer group Which? claiming that variations in cost and availability of music downloads from country to country were unfair to consumers.

News of the video service came as Apple faced a further challenge to its dominance - this time from Nokia, the world's biggest mobile phone manufacturer. The Finnish firm yesterday threw down the gauntlet by announcing its service Ovi, a music download deal aimed at European customers. It also unveiled four new handsets designed to challenge the iPod and the forthcoming iPhone, which is set to appear in Britain before Christmas.

The music download service will charge 79p a track - the same price as iTunes' music downloads and much less than many of the music shops offered by the mobile operators themselves. It will let customers load CD collections on to a computer and move them on to a Nokia phone. But Ovi, due to launch at the end of the year, may face difficulties if it goes into direct competition with the phone networks' own music products. Some mobile networks are already threatening to block the Nokia service altogether by refusing to sell handsets compatible with it.

The concern is that if Nokia cannot secure deals with companies such as Vodafone, Orange and O2 British customers who have signed up to the music service could end up paying extra for downloading tracks over the air. Nokia's chief executive, Olli-Pekka Kallasvuo, admitted Ovi owed a lot to the success of the iPod, but said the store - which has already signed up the world's four big record labels - would have a catalogue of "millions" of tracks. "Our target is to have all the music in the world available to everybody," he said.

Apple's TV downloads will also face stiff competition, not least from British TV companies, most of which have launched video-on-demand; some of the shows are free for a time.

But one industry analyst said Apple's video prices were competitive in relation to other options open to British consumers. "In some cases iTunes UK is cheaper than the DVD format," said Arash Amel, chief analyst with Screen Digest.

Vint Cerf, one of the creators of the internet, told the MediaGuardian Edinburgh International TV Festival this week that downloading would eventually replace broadcasting as the dominant force in television. He said 85% of all video watched was pre-recorded; consumers would still need live television for events in the news and sport but increasingly would "download content to look at later".

Mr Amel predicted that the UK download market would be worth £65m within four years, with Apple taking the dominant share.